Process for producing fibrous material



May 26, 1931. s, D, WELLS 4 1,807,111

PROCESS FoR- PRODUCING FIBRoUs MATERIAL Filed Sept. 27, 27

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Patented May 26, 1931 UNITED VSTATES PATENT VOFFICE:

SIDNEY D. WELLS, OF QUINCY, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE MINE 65 SMELTER SUPPLY COMPANY, OF DENVER, GOLORADO, A CORPORATION OF COLORADO PROCESS FOR PBODUCING FIBROUS MATERIAL Application led September 27, 1927. Serial No. 222,353.

My invention relates to improvements in processes for producing brous material and more specifically to the production of straw pulp, although applicable to the production of Vother varieties of pulp.

In 'the roduction of straw and other varieties o ulp, the materialis first treated to a mil digestion with suitable chemicals, as is well known in the art, to the point Where the bond between the fibers and the cells is reduced, but not completely removed. After this treatment, the material is mechanically disintegrated and beaten to produce the finished pulp.

If the material is beaten in the presence ofthe spent cooking or digesting liquors, the fibers are injured by the products of decomposition from the cooking operation being beaten into the stock with the attendant loss of cellular matter, the product.

An important object of `my invention is to obviate these diificulties by a treatment 'of the stock in which the stock is washed free from the spent .cooking liquor before being beaten. l

Other;` objects and advantages of my inventionwill be apparentdurmg the course of the following description.

In the accom anying drawing which forms a part of thls specification andwherein like characters of reference denote like parts throughout the same,

The igure is a more or less schematic rep- -and lower quality of 5 resentation of the apparatus used by my process, illustrating the sequence of the var' ious steps thereof.

In carrying out my process, the stock, which has been treated toa mild digestion with suitable chemicals to the point where the bondbetween the fibers and the cells is reduced but not completely removed, is

Vtaken from the rotary or storage, and passed through a shredder or pulverizer illustrated diagrammatically-at 1, together with wash Water taken from a subsequent point inthe process through pipe 2. The shredder is referably, but not necessarily, of the swing ammer type, and the stock is-shredded therein without washing and put into a From the stuff chest 3 the stock, which is mixed with wash water and in condition to be readily pumped, ispumped by pump 5 to a gate box 6 of the usual constructlon where it is maintained at a constant level by the pump 5 and overflow pipe 7 leading back to the stuff chest 3. The proper quantity of stock passes through the gate 8 into the m1x1ng compartment 9 of the cylinder washing machine designated generally at 10 where it is mixed with liquid from a subsequent point in the proces supplied through pipe 11.

The rmxture passes on to cylinder mold 12 where a sheet is formed and taken off by couch roll 13. from whence it is scraped into the mixing box 14, the spent cooking liquor washed from the cooked stock pass-y ing from cylinder mold 12 through pipe 15 to the sewer.

The sheets scraped .from couch roll 13 are mixed with fresh water from the pipe 16, 1n the mixing box 14 by means of the agitator 17, and the thoroughly mixed Water and pulp pass on to cylinder mold 18 Where the pulp is n again formed into a sheet, picked up by couch roll 19 and scraped into trough 20, the water passing from cylinder mold 18 through pipe 21 to pipe 11 which supplies pipe 2 and mixing chamber 9 with the wash water, by means of centrifugal pump 21.

Trough 20 conveys the thoroughly washed stock to the rod mill 22 y"Where it is rolled and beaten by the freely tumbling rods therein as is fully set forth in my application No. 49,461, filed August 10, 1925 which matured into Patent No. 1,654,624 of J anuary 3,'1928.v While I have illustrated a rod mill, and prefer to use the same, it is to be understood Athat I do not limit myself to l this type of beater but contemplate ,the use of other types of beaters or refining engines, as for instance, a Jordan engine.

The stock is beaten in the rod mill 22, or other beating or refining engine, to the desired degree and passes into stuff chest 23 where it is maintained in uniform consistency by the agitator 24, in condition to be pumped to the paper machines by pump 25.

In the process as outlined above the stock is first shredded without washing, preferably in a swing hammer shredder, where it is put into a condition whereby it can be pumped without difficulty. It can then be pumped over a cylinder mold type of washer which is much more efficient for the purpose than the drum washers now used on beaters.

Vhen the stock has been thoroughly washed,

it can be beaten to the desired degree without the injury to the fibers or quality-of the product like that which takes place when the stock is beaten in the presence of the spent cooking liquor. In the process as formerly practiced, however, the cooked straw is Ataken into beaters provided with drum washers, and'washed while it is beaten. a This method of beating'a'ndwashing at the same 4operationis not only detrimental to the .s trawstock, but requires much greater quantities of Water than the system which I have outlined. It is also true that even with the larger quantities of water used inthe `old process, the straw paper contains from 30 to 40 per cent of the line originally used in the cook. I

In my process the .steps of shredding,

' washing and beatingare carried out separately -and inde endently, withthe use of a Small amount o water as compared with the old processes, and a higher quality of product is obtained.

Having thus describedmy invention what Iclaim and desire to protect by Letters Patent is .i

1. The process of producing fibrous material whichfconsists in treating the material softened material in the presence of water,

pumping the shredded material to a Washing device, thoroughly washing the shredded material to free it from the spent cooking liquor, conveying it to a beating device and beatin it to the desired degree.

3. T e process of' producing fibrous material which consists in treating the material to a mild chemical digestion to the point where the bond between the fibers and the cells is reduced but not completely removed, subjecting the softened material to mechanical disintegration in the presence of water to the point where the water may gain -ready access to its fibrous constituents and the fibers are not completely isolated, washing the disintegrated material with water in the absence of any heating action to free the material fromvthe spent cooking liquor, and completing the mechanical disintegration of the previously washed material.

4. The process of producing fibrous material which consists in shredding the material in the presence of water, agitating the shredded material to thoroughly mix it with the Water, washing the shredded material, and subjecting the washed material to the action of freely tumbling elements in a rotating drum.

5. The process of producing fibrous material, which consists in treating the material to a mild chemical digestion,shred ding the softened material in the presence of water,`mixing the material with the water, washing the spent cooking liquor from the material," and subjecting the washed material to the action of freely tumbling elements in a rotating drum.

6. The process of producing fibrous material which consists in treating the material to a mild chemical digestion, shredding the softened material in the presence of" water, agitating the shredded material and water, washing the material to free it from the spent cooking liquor, subjecting the washed material to the action of freely tumbling elements in a rotatin drum, and agitating the material to maintain it at uniform consistency.

7. The process of producing straw pulp which consists in treating the straw to a mild chemical digestion, shredding the softened straw in the presence of water, agitating the straw and water, Washing the straw, mixing with fresh water and rewashing, and subjecting the thoroughly washed straw to the action of freely tumbling elements in a rotary drum.

8. The process of producing straw pulp which consists inl treating the straw to a mild chemical digestion, shredding the straw in the presence of'water taken from a subsequent point in the process, agitating the shredded straw and water, mixing the straw with water from a subsequent point in the process, washing the spent cooking liquors from said straw, draining the spent'cooking liquor, mixing the straw withfresh water, washingthe straw Lin the fresh water and subjecting the washed straw to the action of freely tumbling elements in av rotating drum.

9. The process of producing straw pulp which consists in treating the straw to a mild chemical digestion, shredding the straw in the presence of water taken from a. subsequent point in the process, Washing the straw in a counter current washing device and subjecting the washed straw to a beating and refining treatment.v

1()h The process of reducingv terial which consists 1n treating the fibrous material to a mild 'chemical digestion, shreddin the material in the presence of water, was ing the material in a counter current washing device to free it from the spent cooking liquors, and subjecting the Washed material to al beating and refining treatment.

11. The process of producing fibrous ma terial which consists in treating the material to a mild chemical digestion, shredding the ,softened material in the presence of water,

mixing the material Vwith the water and conveying it to awashing device, Washing the spent cooking liquor from the material, and .i

subjecting the washed material Vto the action of beating elements.

.12. The rocess of producing fibrous material which) consists in-partially disintegrating the material to the point at which the interstices in the material do not obstruct the `passage of Water insoluble impurities,

- washing the partially disintegrated madisintegrating the material in the resencev l the passage of water insoluble impurities,

terial to remove impurities, and then mechanically disintegrating the washed material to the point Where the fibers are completely separated from each other.

13. The process of producing brous materialwhich consists m subjecting the material to a. mild chemical digestion, partially of the cooking liquors to the oint W ere the interstices in the material o not obstruct washing the partially disintegrated material to remove impurities, and then mechanically dlsmtegratlng `the washed material to 'the point where the fibers are completely sepa- 1 rated from each other.

`to remove impurities therefrom, and then subjecting the washed material'to the action 14. The rocess of reducing fibrous material Whic consists 1n subjecting the material to a mild chemical digestion, partially` disintegrating the material in the resence of the cookingliquors to the oint w ere the interstices in lthe material o not obstruct the passage ofy water insoluble impurities, washing'the partially disintegrated material of freely tumbling elements in a. rotating drum to completely separate the fibers from each other in the `absence of cooking liquors and other impurities.

testimony whereof I aix my signature. SIDNEY D. WELLS.

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